G Edwards

Bio: G Edwards is an academic researcher from University of Manchester. The author has contributed to research in topics: Ion trap & Instrumentation (computer programming). The author has an hindex of 2, co-authored 7 publications receiving 11 citations.

A compact linear Paul trap cooler buncher for CRIS

Abstract: A gas-filled linear Paul trap for the Collinear Resonance Ionisation Spectroscopy (CRIS) experiment at ISOLDE, CERN is currently under development. The trap is designed to accept beam from both ISOLDE target stations and the CRIS stable ion source. The motivation for the project along with the current design, simulations and future plans, will be outlined.

A compact RFQ cooler buncher for CRIS experiments

Abstract: A compact radio frequency cooler buncher (RFQCB) is currently in development between The University of Manchester, KU Leuven, and CERN. The device will be installed as part of the Collinear Resonance Ionisation Spectroscopy (CRIS) experiment at the Isotope separator On-line device (ISOLDE) at CERN. The purpose of developing a dedicated RFQCB for the CRIS experiment is to increase data collection efficiency, and simplify the process of obtaining reference measurements with stable isotopes. The CRIS technique is outlined in addition to an overview of the proposed RFQCB, and its potential compatibility for implementation at ISOLDE.

Laser spectroscopy of indium Rydberg atom bunches by electric field ionization.

Abstract: This work reports on the application of a novel electric field-ionization setup for high-resolution laser spectroscopy measurements on bunched fast atomic beams in a collinear geometry. In combination with multi-step resonant excitation to Rydberg states using pulsed lasers, the field ionization technique demonstrates increased sensitivity for isotope separation and measurement of atomic parameters over previous non-resonant laser ionization methods. The setup was tested at the Collinear Resonance Ionization Spectroscopy experiment at ISOLDE-CERN to perform high-resolution measurements of transitions in the indium atom from the $$\text {5s}^2\text {5d}\,^2\text {D}_{5/2}$$ and $$\text {5s}^2\text {5d}\,^2\text {D}_{3/2}$$ states to $$\text {5s}^2n$$p $$^2$$P and $$\text {5s}^2n\text {f}\,^2$$F Rydberg states, up to a principal quantum number of $$n=72$$. The extracted Rydberg level energies were used to re-evaluate the ionization potential of the indium atom to be $$46,670.107(4)\,\hbox {cm}^{-1}$$. The nuclear magnetic dipole and nuclear electric quadrupole hyperfine structure constants and level isotope shifts of the $$\text {5s}^2\text {5d}\,^2\text {D}_{5/2}$$ and $$\text {5s}^2\text {5d}\,^2\text {D}_{3/2}$$ states were determined for $$^{113,115}$$In. The results are compared to calculations using relativistic coupled-cluster theory. A good agreement is found with the ionization potential and isotope shifts, while disagreement of hyperfine structure constants indicates an increased importance of electron correlations in these excited atomic states. With the aim of further increasing the detection sensitivity for measurements on exotic isotopes, a systematic study of the field-ionization arrangement implemented in the work was performed at the same time and an improved design was simulated and is presented. The improved design offers increased background suppression independent of the distance from field ionization to ion detection.

Exploring the magical tenacity of doubly closed-core nuclei with gallium and francium isotopes

Abstract: This thesis presents nuclear spins, electromagnetic moments, and changes in the mean-square charge radii for radioactive gallium isotopes, and the latter two for the francium isotope 214Fr with additional α-decay spectroscopy. Measurements were made using the CRIS technique at the ISOLDE facility in CERN, facilitating some of the most sensitive nuclear structure studies on exotic nuclei to date. Where applicable, experimental results are compared to empirical, and LSSM calculations. The amalgamated data set has presented the opportunity of probing the sturdiness of three doubly-magic nuclei with respect to their local vicinities: 56Ni, 78Ni, and 208Pb. A magical 56Ni core is confirmed with an electromagnetic-moment analysis of 65,67,69Ga, albeit of a soft nature. Comparisons with shell model calculations not only confirm increased mixtures of π2p3/2/π1f5/2 configurations and the presence of neutron correlations towards N = 28, but they also highlight systematic trends with respect to the neighbouring odd-Z isotope chains. Analyses of neutron-rich species up to 82Ga reveal a rich collection of nuclearstructure effects: a gradual proton-occupation migration from π2p3/2 → π1f5/2 for the odd-A species which culminates in a ground-state spin reversal involving those spins at 81Ga, isomeric presence in 80Ga at N = 49, and a kink in the change in the mean-square charge radii for 82Ga at N = 51. Overall, this adds further evidence for a robust doubly magic 78Ni core. Measurements of 214Fr with t1/2 = 5 ms represents the shortest-lived isotope to have been measured with laser spectroscopy techniques at an online facility, in which the ISOL production mechanism is the limiting factor. With its g factor suggesting a relatively pure (π1h9/2 ⊗ ν2g9/2) configuration for I = 1− and a kink in its charge-radii value at N = 127, the magical effects of 208Pb can be observed five protons away.

Laser spectroscopy of indium Rydberg atom bunches by electric field ionization

Abstract: This work reports on the application of a novel electric field-ionization setup for high-resolution laser spectroscopy measurements on bunched fast atomic beams in a collinear geometry. In combination with multi-step resonant excitation to Rydberg states using pulsed lasers, the field ionization technique demonstrates increased sensitivity for isotope separation and measurement of atomic parameters over non-resonant laser ionization methods. The setup was tested at the Collinear Resonance Ionization Spectroscopy experiment at ISOLDE-CERN to perform high-resolution measurements of transitions in the indium atom from the 5s$^2$5d~$^2$D$_{5/2}$ and 5s$^2$5d~$^2$D$_{3/2}$ states to 5s$^2$($n$)p~$^2$P and 5s$^2$($n$)f~$^2$F Rydberg states, up to a principal quantum number of $n$ = 72. The extracted Rydberg level energies were used to re-evaluate the ionization potential of the indium atom to be 46670.1055(21) cm$^{-1}$. The nuclear magnetic dipole and nuclear electric quadrupole hyperfine structure constants and level isotope shifts of the 5s$^2$5d~$^2$D$_{5/2}$ and 5s$^2$5d~$^2$D$_{3/2}$ states were determined for $^{113,115}$In. The results are compared to calculations using relativistic coupled-cluster theory. A good agreement is found with the ionization potential and isotope shifts, while disagreement of hyperfine structure constants indicates an increased importance of electron correlations in these excited atomic states. With the aim of further increasing the detection sensitivity for measurements on exotic isotopes, a systematic study of the field-ionization arrangement implemented in the work was performed and an improved design was simulated and is presented. The improved design offers increased background suppression independent of the distance from field ionization to ion detection.

Recent Developments in the Synthesis of Cinnoline Derivatives

Abstract: Crinnolines can serve as unique and versatile class of heterocycles especially in fields related to synthetic and pharmaceutical chemistry owing to their potent biological activities. They possess diversity of pharmaceutical activities as anticancer, antibacterial, anti-inflammatory, anti-allergic as well as anti-hypertensive activities. Since the first synthesis of cinnoline by Richter (1883) numerous protocols for their synthesis have been developed utilizing arenediazonium salts, aryl hydrazines and arylhydhydrazones precursors. Recently metal catalyzed C-C and C-N bond formation reactions have emerged as efficient tools for synthesis of cinnoline derivatives. This review aims to focus on the recent synthetic routes used for the synthesis of cinnoline derivatives. An effort has been carried out to provide an overview of practical methods for preparing cinnolines. Furthermore the reaction mechanisms have been described in brief.